1. Field of the Invention
The present invention relates to a condensation curable type room temperature curable fluoropolymer composition, particularly a composition excellent in fast curability and deep-portion curability; and to fluorine-containing organosilicon compounds suitable for obtaining elastomers useful in, for example, rubber materials and release agents, a method of producing said organosilicon compounds; and room temperature curable silicone compositions containing the same compounds.
2. Description of the Background
Conventionally, as a condensation curable type room temperature curable composition, there are known those containing, as a base component, a polymer, the backbone chain of which consists of organosiloxane structures or polyoxyalkylene structures and which has a crosslinking point at both ends of the molecular chain. Since these compositions are liquid prior to curing, they are excellent in processability. Further, the resulting cured product is excellent in heat resistance, weatherability, electrical properties, processability and the like, so that it is employed in various fields. However, since the cured product is inferior in chemical resistance, solvent resistance and oil repellant properties, its uses are limited.
While, room temperature curable fluoropolymer compositions comprising, as a main component, a fluoropolymer, the backbone chain of which consists of fluorine-containing polymer structures, having a hydrolyzable group at both ends of the molecular chain; a crosslinking agent; and optionally a catalyst is described in, for example, Japanese Patent Publication (Kokoku) No. 63-61336, U.S. Pat. No. 3,950,588 and EP 0151877. The curing of these compositions proceeds as the hydrolyzable group at the ends of said fluoropolymer and the crosslinking agent undergo dehydration condensation by water present in the atmosphere to be cured. The room temperature curable fluoropolymer compositions are not only excellent in processability prior to curing and cured products obtained by curing the same are excellent in heat resistance, weatherability and electrical properties, but also are superior in chemical resistance, solvent resistance and oil repellant properties.
However, these conventional room temperature curable fluoropolymer compositions are slow in curing rate, and especially it requires a long time for curing the deep portions thereof when left to stand in the atmosphere, compared to curable compositions comprising, as a main component, a polymer of which backbone chain consists of organopolysiloxane or polyoxyalkylene. For example, it requires a time of 1 to 2 weeks for curing from the surface to 5 mm in depth of said curable fluoropolymer composition at room temperature in the atmosphere. That is, these compositions have the defects of being extremely poor in fast curability and deep-portion curability. This is because the water content in the atmosphere is hardly to permeate into the fluoropolymer.
On the other hand, organofluoro compounds are employed in various fields. For example, elastomers obtained by crosslinking the organofluoro compounds at a high temperature of 150.degree. C. or more with a crosslinking agent are used as rubber materials and release agents. Although most of elastomers obtained from the conventional organofluoro compounds are unsatisfactory in chemical resistance, especially solvent resistance, resistance to acids and resistance to bases. Further, although elastomers to be used in, for example, sealants and molded products are desirable to be excellent in said chemical resistance and otherwise in releasability and water repellant properties, and to cure at room temperature, organofluoro compounds capable of producing such elastomers have not hitherto been known.